The present invention relates to a printing press.
The Sammeldruck printing method is known as a special printing method capable of performing multicolor printing at once by applying inks of a plurality of colors to separate portions of one plate surface. A related Sammeldruck printing press that executes the Sammeldruck printing method is, e.g., one having an arrangement as shown in FIG. 5.
A Sammeldruck printing press 21 shown in FIG. 5 is an apparatus that performs Sammeldruck printing on a sheet 22, and includes a printing unit 23. The sheet 22 is transported on a transport path 26 constituted by an impression cylinder 24 of the printing unit 23 and a transport cylinder 25 in contact with the impression cylinder 24.
The printing unit 23 includes the impression cylinder 24, a blanket cylinder 28 in contact with the impression cylinder 24, a collecting plate cylinder 29 in contact with the blanket cylinder 28, a collecting blanket cylinder 30 in contact with the collecting plate cylinder 29, two partial plate cylinders 31 in contact with the collecting blanket cylinder 30, and two inking devices 32 that supply ink to the partial plate cylinders 31. A printing configuration having the cylinder array of the impression cylinder 24, the blanket cylinder 28, the collecting plate cylinder 29, the collecting blanket cylinder 30, and the plurality of partial plate cylinders 31 is called a Sammeldruck configuration. In the Sammeldruck printing press 21, a dry offset plate 33 and dry offset plates 34 are mounted on the collecting plate cylinder 29 and the two partial plate cylinders 31 in the Sammeldruck configuration, respectively.
In Sammeldruck printing by the Sammeldruck printing press 21, a plurality of colors are printed on the same drawing line without misregistration, and a drawing line whose color changes midway can be printed. Sammeldruck printing has a feature in which no misregistration occurs, and is often employed to prevent forgery of printing products. A printing press employing Sammeldruck printing is disclosed in, e.g., Japanese Patent Laid-Open No. 2013-86437.
Printing presses as described above are strongly requested to perform more advanced forgery prevention printing.